1. Field of Invention
The present invention relates to television technology, in particular, to a method and apparatus for real-time testing and adjusting of television picture colors.
2. Description of Related Art
During shooting, editing, transmitting, and receiving of television programs, the pixels of video signals may be attenuated and thus become distorted due to various factors, resulting in disharmony and fade of actually received pictures, presenting the audience a stale, unreal, or even depressive feeling.
Currently, the real-time adjusting of television picture colors is for the whole picture, that is, unidirectional adjustment instead of separate real-time testing and adjusting of colors at each pixel. For instance, it is impossible to adjust the picture of lawn to be brighter green or human skin to appear lifelike and ruddy.
The present invention is to provide a method and apparatus for real-time testing and adjusting of television picture colors that can perform real-time testing and adjusting of colors at each pixel, thus presenting views vivid and appealing television pictures.
The objective of the present invention is implemented by a real-time testing and adjusting method for TV-picture color, which includes the steps of providing a chromatic-coordinate testing circuit and a chromatic-coordinate bias circuit that is connected to the output of the chromatic-coordinate testing circuit so as to adjust each color; receiving TV signals by the chromatic-coordinate testing circuit, identifying by the chromatic-coordinate testing circuit a pixel of identity feature as the one to be chromatically biased; and controlling by the chromatic-coordinate bias circuit the bias applied to the video-driving amplifier of the TV set.
The controlling step further includes the increasing or decreasing of either output of bias current or output of bias voltage by a resistor.
The pixel of identity feature is the one to be biased, which refers to that the television signal has the parameters characteristics of the pixel or is a signal with certain characteristics after being processed.
The identifying step is to compare received video signals, comprises of the step of presetting the signal that corresponds to the pixel to be chromatically biased to be proportional to a particular value or signal components after comparison. The pixel is determined as the one to be chromatically biased after the compared result is consistent with the preset value.
The comparison can be performed separately or simultaneously for signal components.
The chromatic-coordinate testing circuit attenuates the three primary colors (RGB) signals respectively so as to make the R, Q and B values of the pixel to be chromatically biased identical.
The television signals include three primary color (red, green, and blue) signals, color difference signals, component signals, modulation signals, and digital signals.
When the television signals are color-difference signals, component signals, or modulation signals, a decoder converts them into three primary color (R, G5 and B) signals and then forwards them to chromatic-coordinate testing circuit.
When the television signals are color-difference signals, component signals, or modulation signals, the chromatic-coordinate testing circuit and the chromatic-coordinate bias circuit test and adjust these signals, and after the decoder converts them into three primary color (R, Q and B) signals, output the bias signal to the video-driving amplifier.
When the television signals are digital signals, the comparator of the chromatic-coordinate testing circuit compares the signals with digital codes of the pixel to be chromatically biased that are read from a memory. A controller of the chromatic-coordinate testing circuit receives the output of the comparator and forwards biasing signals to the video-driving amplifier.
When the television signals are the three primary color (R, Q and B) signals, color-difference signals, component signals, or analog signals for modulation signals, an A/D converter converts the analog signals into digital values, then the digital values are compared with corresponding signal values of the pixel to be chromatic-biased that are read from the memory. The controller of the chromatic-coordinate bias circuit receives and amplifies the output of the comparator, and forwards biased signal to the video-driving amplifier.
In the controlling step, the changing of the output applied to the video-driving amplifier is performed by setting up the gain of the amplifier in the chromatic-coordinate bias circuit according to the amount to be adjusted.
A real-time testing and adjusting apparatus in accordance with the present invention comprises a chromatic-coordinate testing circuit for adjustment of colors and chromatic-coordinate bias circuits coupled to each output of the chromatic-coordinate testing circuit; the input of the chromatic-coordinate testing circuit is the television signals while the output of each chromatic-coordinate bias circuit is coupled to the video-driving amplifier.
The chromatic-coordinate testing circuit comprises an attenuation circuit, an AND logic gate, and an OR logic gate. The input of the attenuation circuit receives color television signals including RGB signals, the inputs of the AND logic gate and the OR logic gate are coupled in parallel with the output of the attenuation circuit respectively. The chromatic-coordinate bias circuit comprises a biasing circuit, a comparator, and an amplifier. The first input of the comparator is coupled to the output of the AND logic gate and the second input is coupled to the output of the biasing circuit. The input of biasing circuit is coupled to the output of the OR logic gate. The output of the comparator is coupled to the amplifier, and the output of the comparator is coupled to the video-driving amplifier.
The real-time testing and adjusting apparatus in accordance with the present invention further comprises a decoder arranged before the attenuation circuit of the chromatic-coordinate testing circuit to convert the color-difference signals, component signals, or modulation signals into RGB signals; the decoder may also be arranged between the comparator and amplifier to convert the tested and adjusted color-difference signals, component signals, or modulation signals into RGB signals.
In case of digital signals, the chromatic-coordinate testing circuit and chromatic-coordinate bias circuit comprise a microprocessor-based controller, a comparator, and a memory. Digital signals are applied to the first input of the comparator and the output of the memory is coupled to the second input of the comparator. The output of the comparator is coupled to the controller, and the output of the controller is coupled to the comparator and memory respectively. The output of the controller is coupled to the video-driving amplifier.
When the television signals are three primary color (RGB) signals, component signals, or analog signals of the modulation signals, the chromatic-coordinate testing circuit and chromatic-coordinate bias circuit comprise a microprocessor-based controller, an A/D converter, a comparator, a memory, and an amplifier. Analog signals are converted by the A/D converter into digital signals and forwarded to the first input of the comparator. The second input of the comparator is coupled to the output of the memory. The output of the comparator is coupled to the controller. The control terminal of the controller is coupled to the comparator and memory respectively. The output of the controller is coupled to the amplifier, and the output of the amplifier is coupled to the video-driving amplifier.
The invention method and apparatus for real-time testing and adjusting television picture colors are implemented through setting the chromatic-coordinate testing circuit and the chromatic-coordinate bias circuit, providing a solution to the distortion of color signals for television picture by adjusting the level of color signals.
The pixel having identifiable characteristics in accordance with the present invention refers to either the characteristics of various signals corresponding to the pixel to be biased or the characteristics appearing after being processed, such as the equal values for attenuated red, green and blue. The television signals having the parameter characteristics of the pixel in accordance with the present invention refer to that the values of three primary color signals (RGB), color-difference signals, component signals, modulation signals, and digital signals corresponding to chromatic-coordinate pixel, and these signal values which after being processed (such as attenuation) all have its respective correlation with the chromatic-coordinate pixel.
As shown by experiments, the adjusted television pictures appear fresher and brighter than what they were before the adjustment, tree leaves and lawns (appear as )greener and human skin (appear as) ruddier, thereby providing a more vivid and vigorous screen effect. With a method of similar mechanism and an apparatus of similar structure, the present invention can also perform testing and adjusting for color-difference signals, component signals and modulation signals. Through variation of the embodiment of the chromatic-coordinate testing circuit and the chromatic-coordinate bias circuit, the technology in the present invention can also be applied to either digital televisions or analog televisions.